Holland cloth and its method of manufacture



D. C. MCROBERTS HOLLAND CLOTH AND ITS METHOD OF MANUFACTURE Sept. 15, 193.1.

Filed July 3l, 1928 IU i HUN!! .ZDOnaZ C. MC'

ATTORNEY Patented Sept. 15, 1931 I tenuta UNITED STATES PATENT OFFICE DONAL C. MGROBERTS, OF DETROIT, MICHIGAN-,-ASSIGNOR T MORGAN & IVRIGHT, OF

DETROIT, MICI-IIGAN,` .A CORPORATION OF 1VIICI-I2IIC1`rANY HOLLAND CLOTH AND ITS METHOD 0F MANU-FACTURE Application filed July 31,

This invention is concerned generally With fabric material and particularly to cloth sheeting adapted for hollandl making.

In the rubber art, holland clothis employed for a variety of purposes, the principalA ones being its use as a liner or carrier for sheeted unvulcanized stocks that are prepared' for trade use, as a liner to be used temporarily to facilitate calendering of unvulcanized gums into sheets, and also as a liner for calendered strips of so called bologna gum thatv enters into various products in the factory. For Whatever purpose holland is used in connection with rubber, itsV function remains substantially the same, namely, to preserve the smooth surface of the carried sheet of unvulcanized gum and to prevent` oneregion of the tacky gum froln adhering to another. These functions are best obtained Whenvthe holland has a tightly adhering surface sizing of high gloss and when it is free from Wrinkles, folds, bagging in the center, cockled surface, or in general, any condition tending to prevent the cloth-from lying perfectly fiat `and smooth when placed upona-flat surface.

Holland cloth heretofore produced hasnot possessed this flat characteristic due in some cases to the fact that in Weaving the cloth there has been greater tension applied to the Warp threads `constituting the selvage edges than to the Warp threads in the intermediate regions of the sheet, Witlithe result that'the finished sheeting is longer in the intermediate regions than at the selvage edges which are perfectly straight and taut.

In calendering the sized surface of the holland sheeting to render the same smooth and glossy, the holland passes through a calendering machine under tension to avoid Wrinkling. With sheeting of tight edge and baggy center construction it is obvious that-sufficient tension to avoid all Wrinkling cannot be applied Without danger of breaking the relatively stretchless selvage edges which are already under greater tension and thereby cause a tear across or partially across the sheeting. Furthermore, a roll'of'such cloth Wound'un'- der the usual vtension Will be foundvary hard or tight' at the edges but soft and mellow at the intermediate regions.: rIhis condition'is 1928. vSerial No. 296,622.v

likewiseftrueV after a sheet` of calender'ed gum has'sbeen appliedlto-the holland andthe assembly Wound under tension into atight roll. The assembly isf compressed tightly at the edges between adjacent rounds but the mid portions are not under tension and therefore present a baggy or roughened condition which causes Wrinkles, folds, or other faults in the Oumitself, rendering large areas thereof uniit for` use.

It is therefore an object of this invention to lovercome the fore-goingdisadvantages and to produce a cloth sheeting in Which the tension atl the selvage edges is not more than the tension in the intermediate regions ofthe cloth,.andto provide this cloth With al suitably.` sized and calndered surface, the finished' product forming anew article of manufacture compris-ing holland cloth having a characteristic suc-h that it may be safety put under the proper tension duringcalendering operations either ofthe holland itself or of the assembly comprising the holland and the carried sheet of unvulcanized gum, and fur.- thercapable' of being Wound into tight rolls Without causingtlie roughened surface heretofore unavoidable. Other features and advantages will become apparent as the description proceeds. f

In the accompanyingdravvings forming a part'of this specification; v Fig. is'a perspective view of a piece of holland cloth having tensionless selvage edges and smooth surface sizing;

Fig. 2 'is' a sectional View of a roll'of gumcarrying holland having tensionless selvages;

.Fig 3 is a diagrammatic view indicating one methodof producingtensionless selvage edges; y

IFig: L represents-another method of producing tensionless selvages; and

Fig. 5 is a perspective vievvof a piece of looped edge holland" cloth having' surface sizing.

Referring to the drawings, particularly to Fig. l, the reference numerallO represents a piece of square-Woven cloth sheeting having tensionless or wavy selvage edges 11 resulting from Weaving the cloth With less tension applied' tothe Warp threads-12 constituting similar in character to the well-known rubber spreading machines) in which a covering of dough-like starch sizing is scraped into both the top and bottom surfaces of the sheet. This operation provides the sheeting with sized surfaces but the sizing is rough and glossless. In order to render these surfaces smooth and glossy, the sheeting is subjected to a number of calendering operations in a calendering machine which may be of the commonly known type usually including three smooth cylindrical steel rolls arranged vertically one above the other, the Vrolls being cored out and steam heated and perfectly straight from side to s ide, that is, not crowned. The sized and dried sheeting is trained through the calender between the bottom and middle rolls passing through the machine and on to a take-up shell to the back thereof. As soon as the sheeting is started into the calender, the tension is applied usually by means of hydraulic rams raising the lower roll against the sheeting and that in turn against the middle roll. The pressure and heat of the rolls against the surfaces of the sheeting performs an ironing operation and the greater the number of these operations, the smoother will be the surfaces and the higher the gloss. During thiscalendering operation, it is necessary that the applied tension be sufficient to straighten any bagging tendency in the middle of the sheeting and to avoid wrinkling.

The sheeting as heretofore produced had tight selvage edges. In other words, the cloth was woven with more tension applied to the selvages than to the midvregions of the cloth and as a result of this construction, it was not possible to apply uniform tension to the body of the cloth in a calendering machine without setting up excessive tension 1n the relatively tight selvage` edges and thereby causing breaks and tearing across the sheeting. A length of such cloth used as a carrier for a sheet of unvulcanized' gum did not allow the gum to lie flat and smooth during the calendering operation. Furthermore, when this tight edged cloth was wound into a roll under the usual tension the cloth was compacted tighter at the selvage edges than in the mid portions, resulting in a roughened or cockled condition of the gum, and consequent ruination of extensive areas thereof.

The tensionless edged cloth l0 above re- After weaving, the sheeting is` the unwinding warps.

ferred to is not open to the faults inherent with the tight edged construction. When this tensionless edge cloth 10 is fed through `a calendering machine for the various purposes mentioned, the slack selvages 11 pei'- mit the required tension to be safely applied to the body 13 of the cloth for the purpose of causing it to lie perfectly flat and smooth. This tension is preferably suiiicient lto straighten or pull the slack out of the loose edges 11. In this manner, the entire area of the `sheeting 10 is run through the calender in a perfectly flat or prone condition from side to side, the cloth assuming and retaining a drum-like condition entirely free of the wrinking occurring in the old type of cloth. A sheet of gum may be carried by the tensionless cloth 10 with the assurance that it will-lie perfectly flat and `smooth throughout its entire area, either while in the calendering machine or when eventually wound into tight rolls.'

In this connection attent-ion is called to Fig. 2 in which a roll 18 of sheet gum 19 carried by the cloth 10 lies smoothly and of uniform diameter across the ventire width of the roll. A

For weaving the slack edged cloth illustrated in Fig. 1, several methods may be employed, for instance, in Fig. 3 there is diagrammatically represented a warp beam 20 forming a portion of a cloth weaving'machine, the other elements of which may be of the kind well known in the art and need not 'be illustrated herein. It will be noted that the warp beam 2() is built up or enlargedfin diameter adjacent its ends, as indicated at 21, so that the warp threads 22 `feeding from these enlarged ends 21 to the weaving yelements of the machine, are long- 'er and consequently underless tension than the other regions of the cloth, that is, those regions in which the intermediate warp threads 23 form a part. Warp beams of this type usually include some form of adjustable brake'for controlling the tension of Another y, way of weaving the Fig. 1 cloth, or a cloth in which rthere is not more tension iin the selvage warps than in the intermediate warps, is illustrated in Fig. 4. The warp beam in this 'instance is designated 24 and the thread-carrying reel extends from'side with even -ten- ,sionv of Vall of its threads. 25. A pair of small spools 26 placed at opposite ends of the warp Vbeam 24 supply the necessary threads 27 to form the selvage edges, these threads 27 being Vunder less tension than th main threads 25. f f

A further example of tensionless Weave (Fig. 5) comprises sheeting having looped edge construction 28 which produces tensi-onless edges. Various other weaveslmay be employed to secure the non-tensioning edges, 'and this cloth 'when' combinedwith fri 5 suitable surface sizing 29 forms a new article of manufacture produced by a new method, and comprising a product in which there is no wastage or manufacturing difficulties either during the process of calendering the cloth, or the carried sheet of unvulcanized gum, or, when the finished product is wound into rolls under tension.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

l. As a new article of manufacture, square-woven cloth sheeting of closely spaced warp and weft threads of substantially the same diameter and having continuous load sustaining warp threads of greater length at the selvage edges than in all other regions of the cloth to produce a fiat surface upon the loading of the cloth, and sized and calendered surfaces.

2. A new article of manufacture, comprising square-woven cloth of closely spaced warp and weft threads of substantially the same diameter and having continuous load sustaining warp threads of greater length at the selvage edges than in all other regions to produce a fiat surface upon the loading of the cloth, said cloth having a sized and glazed surface carrying a removable sheet of unvulcanized gum.

3. The method of manufacturing holland cloth, which consists in weaving said cloth with tensionless selvage edges, applying surface sizing to the cloth placing the body of the cloth under suiiicient tension in a calendering machine to cause said body and said edges to assume fiat drum-like condition from edge to edge and then calendering the entire cloth to produce a glazed surface.

4. The method of manufacturing an assembly consisting of holland cloth and a removable sheet of unvulcanized gum, which consists in weaving said cloth with wavy selvage edges, applying surface sizing to the cloth placing the cloth under suflicient tension in a calendering machine to draw out the waves to fiat form, whereby the cloth assumes drum-like condition from edge to edge, applying the gum to the cloth and then calendering the assembly while under said tension.

Signed at Detroit, county of lVayne, State of Michigan, this 27th day of July, 1928.

DONAL C. MOROBERTS. 

